1. Field of the Invention
The present invention follows what is disclosed in a TIPO patent application with application number 098110021. The present invention relates to a magnetic antenna, especially to a porous magnetic antenna, of which a magnetic layer comprising at least one hole for altering the original field pattern and the gain value of an antenna, so that the antenna can possess stable directionality.
2. Description of the Related Art
In recent years, due to the practical applications of wireless communication and the popularization of hi-tech products, the communication industry has had new breakthroughs and achievements. As a variety of electronic communication products and wireless communication equipments have been applied in our daily life, the antenna, especially the planar antenna, broadly found in the wireless communication systems, is gaining a lot of attention due to its simple manufacture process and small form factor. Common planar antenna includes microstrip antenna, printed antenna, planar inverted-F antenna, etc.
However, the common antenna has fixed characteristics, no matter of what type it is—for example, the EM wave field pattern radiated from an antenna is usually of omni-direction type and can not be changed—while there are occasions where EM wave intensity needs to be enhanced in some specific direction. For example, when using a mobile phone in a tunnel, it is desirable to enhance the antenna's EM wave in the direction towards the exits of the tunnel, or alter the EM field pattern to a directional one directing towards the exits of the tunnel to improve the mobile phone communication quality in the tunnel.
It is found that the Taiwan TW466,799 patent has disclosed an antenna comprising an EMI snubber, which utilizes a magnetic means having soft magnetic powder to cover the antenna for controlling the field pattern to reduce the antenna's EM radiation against human body. However, the magnetic means is mainly for shielding or inhibiting EMI, and the field pattern still does not possess directionality though part of the field pattern is altered.
It is also found that the U.S. Pat. No. 6,768,476 patent “Capacitively-loaded bent-wire monopole on an artificial magnetic conductor” has disclosed an antenna consisting of a thin strip bent-wire monopole disposed on an artificial magnetic conductor (AMC), to achieve an electrically small antenna for use in handheld wireless devices without suffering a substantial loss of efficiency. However, the antenna disposed on an artificial magnetic conductor can not change the antenna's field pattern to enhance the gain in some specific direction, though it can reduce the substantial loss.
Further, it is found that the Taiwan TW466,799 patent “Directional antenna” has disclosed a directional antenna, which utilizes a hybrid magnetic means having soft magnetic powder and an oxide film layer to cover the antenna for shielding or inhibiting EMI, but it still can not change the antenna's field pattern to enhance the gain in some specific direction.
To conquer the disadvantages of the prior art antennas mentioned above, the present invention proposes a porous magnetic antenna.